A.生物學(xué)產(chǎn)量; B.收獲指數(shù) C.經(jīng)濟學(xué)產(chǎn)量; D.經(jīng)濟指數(shù);
A.間作; B.單作; C.混作; D.套種;
A.微生物肥料; B.農(nóng)家肥料; C.化學(xué)肥料; D.復(fù)合肥;